Blowpipe



Nov. 3, 1931. F. s. AUSTIN ET AL 1,830,459

BLOWPIlE Filed May 5l, 1928 2 Sheets-shewV l am N w a N *z Si i Nov. 3, 1931.

F. s. AUSTIN ET AL 1,830,459

` BLowPIPE' Filed May 5l, 1928 2 Sheets-She@ 2 Jffy@ 31A/vauro@ @Houma Patented Nov. 3, 1931 UNITED VSTATES PATENT OFFICE g FRANCIS `S. AUSTIN, OF PITTSBURGH, PENNSYLVANIA, AND LORN CAMPBELL, JR., OF

LAKEWOOD, OHIO, ASSIGNORS TO GAZEBO-OXYGEN CO/IPANY, F vPITTSBURGH, PENN- SYLVANIA, A CORPORATON OF DELAWARE Y BLoWrIrE Appneation sledv May 31,

This invention relates to blowpipes of the type employed for the cutting of metal Vwith oxygen, wherein the preheating and cutting oxygen and the combustible gas are delivered through passages in a head to appropriate passages in a tip carried by the head. It is the general purpose and object of the invention to improve the operation of such pipes in such particulars as securing an efficient admixture of oxygen and preheating gas in the passages provided for such mixture at the delivery end of the tip; to secure a uniform distribution of lsuch mixture to such delivery passages; to supply the preheating mixture through the head to the tipcarried thereby in such manner as to reduce to a minimum the danger and destructivenessof backfire in such head; to enable the head to be maintained comparatively `cool in operation while pre-heating the cutting oxygen; to provide an improved'arrangement in the head of the block in which the preheatinggases are preliminarily mixed; to prevent backfiring through the valve block into the '7 oxygen-supply tube; andto provide a strong connection between the Vhead and the pipes which conduct gases thereto.,

le accomplish the foregoing objects in and through the construction and arrangement of parts shown in the drawings, Wherein Fig. 1 represents a side elevation of a blowpipe constructed in accordance with our invention; Fig. 2 a central sectional View through a blowpipe head and tip and through the ends of the pipes connected to said head; Fig. 3 a detail in sectionand corresponding to the line 3-3 of Fig. 2; Figs. 4, 5 and 6, details in section corresponding respectively to thelines 4-4, 5 5 and '6 6 of Fig. 2; Fig. 7 a plan View of the valve block and part of the tubular handle; and Fig. 8 a sectional detail on the line`88 of Fig. 7. i' Describing the various parts by reference characters, 1 designates a valve block which is provided with a connection 2 for oxygen and a connection 3, controlled by a valve the handle of which is shown at 4, for combustible gas. Thevalve block, as isV common in the art, is provided with a valveoperated by a lever 5 for controlling the supply of cutting 192s. sum1 Nq. 281,959.r

oxygen through a pipe 6 to the head. It is also provided with a passage controlled by a valve 7, for supplying preheatingV oxygen` ablyin the` same plane, the said plane being vertical when. the pipe is in the position shown in Figs. 1 and 2, which position, for convenience of reference in the following description, will be the position in which the pipe is assumed to be used.

It will-'be noted that the pipes 6 and 8,

lwhich are the uppermost and lowermost pipes,fare larger and heavier than the intermediate pipe 9 and that the front ends of the pipes 8 and 6 are adjacent to the top and bottom respective-ly of the head. This arrangement of the pipes', with theuse of heavy upper and lower pipes,`provides a particularly strong connection between the pipes and the head. A

`Above the pipe 8, the head is provided withV anupwardly and forwardly inclined seatf'12, which seatis pierced by a bore 13 extending downwardlyvand forwardly t0- lward the upper portion of a chamber (to be ydescribed hereinafter) formed within the upper portion of the bore 14, which extends upwardly from the bottom of a front extension 15 of the head. The bore 13 is provided with an annular enlargement 13a at the rear thereof forming an annular' distributing chamberywith the mixing plug; the re?V mainder-of .the bore is internally threaded, as shown at 13". Threaded into the bore 13 is a'mixing plug 16 having a head 17 provided witha slot 17a for the receptionv of a screw driver and, having, on the rear or underside of said head, a beveled surface 17b adapted to engage the correspondingly bev'- "eled seat 1 2 at the outerl end of the bore 13. Y

This plug is provided with a reduced body portion 16a extending from the head thereof and forming the annular distributing chamber 18, referred yto hereinbefore, with the part 13a of the bore13. The body of the plug is provided'with two externally threaded portions 19 and 20, the body beingre-V duced between these threaded portions, as

shown at 21, thereby to provide an annular chamber 22 within `the bore 13. The plug is provided with a central bore, the .upper portion 23 of which is of smaller diameter than the lower portion 23a. The upper end of the bore 23 communicates with the chaml te ` This Y chamber 34l inthe head above the outertip establishes -chamber and the pipe 6y for cutting lating with the seat 29a.' body A3 is provided with a plurality of longitudinal slots. 32 which extend from the ber 13 by means of ports 24, while the upper 'end of the bore 23a communicates with they .chamber 22 by means of ports 25. The lower endof'the bore 23a communicates with a chamber 2formed in the bottom of the bore 13.

f The pipe 8 delivers preheating oxygen into the chamber 18 through a bore 27 in the head 11 and the ypipe 9 delivers combustible gas to the chamber 22 by means of a bore 28 in such head 29 denotes a' reduced internally threaded extension of the bore 14, projecting into the head, there being a tapered seat 29a at the upper end of this threaded extension and a chamber 30 above said seat. An elongated upwardly inclined bore 31l inv the head 11 communication between the oxygen.'

The upwardly extending bore y14, 29 and .29e is provided for the reception of a tip,

which will now be described. This tip comprises generally an inner member A and an outer member B. The inner member has a tapered or frusto-conical lower end A', a reduced tapered or frusto-conicalintermedlate portion A2, and a cylindrical upper portion A3. Projecting from the portion A3 is 'an externally threaded head A4. At its extreme upper end, the inner tip member is provided with a beveled surface' A5 cooper- The cylindrical lower end thereof nearly to the upper end of such cylindrical portion. Three such slots are shown, but the numbermay'be varied -as desired without departing from our invention. The lower frusto-conical part A is provided with a plurality of slots .33, six such slots being shown, though the -number also may be varied as desired withloutdeparting from our invention.

The outer member B is shown vas fitted to the inner member, as by swaging, and surrounds the major portion of the cylindrical 'part A3 and the remainder of the inner tip member below 'such Vcylindrical portion. arrangement provides an annular f and the combustible gas -and9. y f

The-oxygen fro-in the V`connection 3 is deliveredinto a 'chamber .40 fromwliiclia pasthe Vsaidboresv and into'tlie passages vand pipes therebeyond; and they deliver the mixture Vof '-preheating gases* tangentially into. and at each side of the said chamber 34, whereby the gases vare whirled and mixed y within said chamber.

' The preheating mixture is delivered from .the slotted4 passages 32 into. the chamber C' 4formed betweentlie outer tip memberand the part A2 of the inner tip member, and thence into the slotted passages 33. It should be noted` here that the passages 33 are out of 585 alignment, or staggered, with respect to the passages 32. Y This ensures uniform distribution of the preheating mixture vfrom| the V.chamber A2 to the delivery passages 33. The chamber30` is arrangedvaxially above 5,90

the central bore 36 in the inner tip member, the centralbore being intended to deliver 4cutting oxygen tothe metal which has been preheated by the mixture delivered through the passages 33. Y

Due to the construction and arrangement of parts, it will .bei-seen that. a strong and hrm connectionV is secured between the head l11 of the blowpipe and the pipes 6, 9 and 8;

that the mixing plug lf3-lis so'rarrangedas to v' -be very readily and conveniently accessible for )ur oses of removal and insertion' that` l P 7 if bach-tire should occur into the 'passages,35, 'the flame therefrom will be located at the sides of the upper portion of the tip and will`- not Vbeso destructive in its action as if the flame were impinging directly 'against the main body'or shank of the tip. Therefore, Vin caseswhere persistent, there willlbe no material injuryv .to-the tip such as will requireits removal and replacement.

such back-fire is not Furthermore, by substi tilting for a single boreV or passage for conducting preheating mixture 'to the chamber34 ya pair of passages each having a cross-sectional areaI substantially half that of such single passage, the. danger of transmitting a backeire through such passages and into the 'chamber Y2G and the parts communicating "therewith is correspondingly minimized.

vThe valve block l is' shown in detail in Figs. 7 Vand 8 and preferably'is af casting havingthethreaded connections 2 'and`3 re- "ferred to hereinbefore andalso valve-,con-

trolled passages'for deliveringthe oxygen to the pipes 6, 3

sa`ge'41 leads toa chamber 42 having a valve seat 43 at 'itsfbottom arranged'to be closed by a ball valve 44 which is pressed to its seat by a light spring 45, the lower end of the spring engaging the ball and the upper end of the spring being seated in acap 46 which is threaded into the top of the chamber. F rom the chamber 42 a short passage 47 delivers the preheating oxygen to a chamber 48,

"the supply of oxygen to such chamber fbeing controlled by a valve 49 threaded into the chamber and having a conical end 492L cooperating with the valve seat at the chamber end of the passage 47. From the cliainberr48, the preheating oxygen is delivered through a short port 50 to a bore'which communicates with the pipe 8.

At the top of the chamber 40 is a valve seat 5l which is adapted to beclosed by a valve 52 within the chamber 40 and havingV a stem 53 extending through a smaller chamber 54 and through the to ofthe valve block i r t) 7 Vthe escape of the gas around vthe outer end of the stein being prevented by packing 55 and a locking plug 55a. The upper end of the stein 53 is arranged to be engaged by the Ylever 5 which has its rear end pivoted between lugs 56 projecting from the block.

-F rom the chamber 54, a passage 5r conducts cutting oxygen to the pipe (i.v

The connection 2 for the coinlaistible gas plied through the pipe 9 bach into the pipe 8 and form an explosive mixture therein,

any back-lire resulting from the ignition of such mixture will be checked'by the valve 44 and prevented from passing therebeyond and into the oxygen supply tube. in placing the torch in operation the valve 49 for preheating oxygen should be closed and the valve t'i'for the preheating fuel gas should be open. rlhen the operator, after opening the valve for the cylinder containing fuel gas, adjusts the pressure on theregulator vand lights the preheating gas to see 'that it is working satisfactorily. He 'should lthen close the valve 6l and open the valve 49, after 'opening the cylinder valve on the oxygen cylinder, and set his pressure by opening the high pressure valve 52; then, when hisworking pressure has been adjusted properly, he closes the valve 49,V opens the valve 'l and lights theV preheating fuel gas at the `burner tip, afteriwhich he opens the valve 49 to securethe proper adinixture 'of oxygen for the vpreheating jets. Where' this procedure is `followed,there is no necessity vfor the check valve 44; but, as found in practice, the, operators do frequently open both valves 49 and 6l, and then open the fuel gas cylinder valve and adjust the pressure. `When this is done,

they then proceed to lopen the oxygen cylinder valve and start adjusting the oxygen pressure. This results in the backing up of the fuel gas through the mixer in the blowpipe head, forming an explosive mixture with the oxygen as it is turned on; fand, if an operator should light the torch immediately after setting-the pressure, a backfire is produced which extends not only into the valve z I,

block, but into the high pressure chamber 40 and'thence into the oxygen hose, which frequently causes severe injury to the operator. 'the check valve 44 prevents the backfire from being transmitted any further than to the chamber containing the saine and prevents the backfire from reaching the high ypressure oxygen chamber 40 and the connecting hose. It has been found that placing the check valve between the chamber 40 and.

the valve 49 is the most eficient location for this valve. Y

Having thus described our invention, what l. A blowpipe comprising, in combination,

a head and a tip secured to said head, the rear end of said head being widened in the direction of a plane extending through the longitudinal axis of the tip and being provided with bores for cutting oxygen, coinbustible gas and preheating oxygen, all of said bores extending from the rear end of Vsaid head, and pipes for conducting cutting oxygen, preheating oxygen, and combustible gas to the bores in said head, the said pipes being connected with the rear end of the head and being arranged with their axes .substantially coincident with the said plane, the pipes'for conducting cutting and preheating yoxygen to the said head being connected adjacent to the bottom `and the top of said lhead, respectively.

2. A blowpipe comprising, incombination, lahead and a tip connected to said head, and means for supplying-cutting oxygen and a i mixture of preheating oxygen and combustible gas to said tip, the said means comprising pipes connected with the rear end of said head for conducting the aforesaid gases thereto, the head Vhaving an upwardly and for' wardly inclined seat` above theY point Y of connection of the uppermost pipe therewith and a bore extending downwardly and forwardly from said seat and in close proximity to the delivery end of the uppermost pipe, a mixing plug threaded in said bore and having a n head adapted to engage said seat, there being longitudinally spaced chamberssurrounding the said plug, the uppermost of saidcharnbers being located in immediate Va head, the said head having a bore-projecting upwardly thereinto from the `lower end thereof, a reduced threaded extension of said bore, and a central chamber above such threaded extension, a tip `comprising .an outer member having its upper end within .said bore and spaced from the threaded extension thereof to provide a chamber below such ex tension, andan inner member threaded into the threaded extensionof said bore and Yprovided with a central bore for cutting oxygen adapted to register with the :central :chamber, the 4said Itip having one or vmore pas sages for preheating .gases .communicating .at their upper ends `with the second chamber, the said head having a bore for cutting oxygen communicating with :the rstchamber, a device in vsaid head for mixing a combustible -gas and preheating-oxygen and said head having bores forsupplying such gas and preheating oxygen to the said device, and rboresextending from the said mixing device and delivering `the preheating mixture formed therein tangentially yto opposite sides of the top of .thesecond chamber.

a. A blowpipe comprising, incombination, a head, the said head having 1a ibore project- Aing upwardly thereinto from vthe lower end thereof, a reduced threaded extension of said bore, and a central chamber f above such threaded extension, a Ytip comprising an outer member having its upper end rwithin said "bore and spaced from the threaded extension thereof to provide a chamber below such extension, and an innervmember threaded into the threaded extension of said Ybore and provided with acentral bore for cutting oxygen adapted to register with the central chamber, the said tip having one or `more :passages for preheating gas communicating at their upper ends with the second chamber, the said head lhaving a bore for cutting oxygen communicating Awith the first chamber, `a device in said head for mixing a combustible gas and preheating oxygen and said head. havf ing bores for supplying such gas and preheating oxygen to the said deviceand 'bores extending from said mixingldev'ice and com- Y .municating with the top of ,the second chamber and on opposite sides thereof, the 'last mentioned bores being restricted to prevent propagation of ame therethrough .and arranged -to deliver the mixture tangentially to Vopposite sides of the ytop of thesecondzchamber.. Y

5. A blowpipe comprising, `in combination,

a head having a chamber and a pair of bores a for delivering a mixture of combustible gas" and preheating oxygen lto the said chamber, the said bores being rest-ricted to prevent propagation of flame therethrough and arranged to `deliver the mixture therefrom tangentially to opposite sides of the top of said chamber, and a Vtip carried by said head and having passages for preheating gases communicating with the said chamber.

6. A cuttingv blowpi-pe comprising a head and a tip carried by said head, the head being provided with passages for cutting oxygen and for combustible gas and preheating oxygen and with a mixer ywith which the lpassages for combustible gas and preheating oxygen communicate a valve block provided with connections for oxygen and combustible gas and having passages therein for such combustible gas and for cutting and preheating oxygen, pipes for conducting such combustible gas, preheating oxygen and cutting Oxyyappropriate pipe extending therefrom vto the blowpipe head. t

7 A blowpipe comprising, in combination, a head and a tip connected to said head, and means for supplying Ycutting oxygen and a mixture of -preheati-ng oxygen and combustible gas to said tip, the said means comprising pipes connected with the rear'end of said head for conducting the aforesaid gases thereto, the head having an upwardly and forwardly inclined seat -above V,the point of connectionof the uppermost pipe ytherewith and a bore `extending downwardly and forwardly from said seat, said bore being located immediately adjacent to the uppermost pipe, a mixing plug in said bore and having a head adapted to engage said seat, vthere being lonn gitudinally spaced chambers surrounding the said mixing plug and communicating with Va central bore therein, the uppermost chamber being located immediately adjacent the delivery end of the uppermost pipe thereby to receive preheating oxygen directly therefrom, and the head 'being provided witha bore for conducting combustible gas to .the second chamber and with 'a bore forrec-eiving cutting oxygen fromthe lowermost pipe.

8. A cutting yblowpipe comprisingfa head and a tipcarried bygsaid head, the `'headbeing provided with passages for cutting oxygen and for combustible gas and preheating oxygen and With a mixer with Which the passages for combustible gas andpreheating oxygen communicate, a valve block having a connection for combustible gas and a valvecontrolled passage extending from such connection through said block, the valve block also having a connection for oxygen, a high pressure chamber into Which such oxygen is delivered from said connection, a valve controlled'passage leading from said chamber through said block for cutting oxygen, and a passage for preheating oxygen conimunieating With said chamber and extending through said block, pipes connecting the passages in the said block With the corresponding passages in the blovvpipe head, a valve in the valve block and controlling the rate of flow of preheating oxygen through the passage therefor in said block, and a check valve in the last mentioned passage in said block and interposed between the last mentioned valve and the high pressure oxygen chamber in said block.

In testimony whereof, We hereunto aiiix our signatures.

FRANCIS S. AUSTIN. LORN CAMPBELL, JR. 

